Hey it's me Destin welcome back to Smarter Every Day. I want to talk about something that's really neat... Um.. I'm atNaval Air weapons station China Lake here in California. I'm in front of a building that does things.. and here is an F-18.. which is a beautiful bird. This particular aircraft can be configured for the attack role or for a fighter role and there's something I want to show you that's way over here check this out. You know all the different weapons on the pylons got some Bombs over there. Look at this. (Pausing to take it in...) This is a Sidewinder missile and this changed a lot of things a lot of places. This is one of the first heat-seeking missiles that was developed here in the50s Right Here China Lake and uh... let's look at it. so you got a Seeker up here so it can go towards the exhaust of a of an aircraft. you've got some kind of pivoting fins right here right? look right here you've got this.. is a side looking proximity sensor which is AMAZING that that's on this model... This is a warhead we'll talk more about the Warhead in a minute... You got the rocket.... And then you get these things in the back look at this... so I want to talk about this... If you look closely... you'll notice there's something that looks like a water wheel here. You see that? Oh it spins! Look at that! So this is called a Now if you can imagine this aircraft is flying along super super fast you shoot this missile at Mach 2.5... You want to stabilize it right? you don't want it to just like Spin and roll so you've got roll, pitch, and yaw right? you don't want this thing to roll in ways that you don't want it to so this is a GENIUS way to get around that so a rolleron, Oh look! You can see right there... you see those little bitty divots? you gotta look close see those little things that are drilled out there? that's where they balanced it because this could span at over a 100,000 RPM and so they had to make some weigh more or less than others so they had to like spin this thing up and balance it like you'd balance a tire by removing material but anyway a rolleron, what it does is as you fire the missile and this spins up you get a flywheel effect so you get a gyroscopic effect and it becomes a giant flywheel like a gyroscope and so that angular momentum gives you an angular momentum Vector that's right there and you can see there's four of them there's one there's two..... there's three..... and there's four. So imagine if you would you're about to fire this missile and if and if you have problems with Dynamic stability in the roll axis because you're an engineer in the 50s and you don't have really fast control loops and digital circuitry at your disposal yet this is a geniu.... this is just genius! because it's a passive Dynamic stability method so imagine you could pin a vector HERE pin a vector HERE here and there and just kind of lock it in space so it'll go straight that's amazing. One thing I don't understand is... there appears to be a pivot point here? so as the missile tries to roll this thing could try to stay in position and so it'll try to stay back where it was and I assume that would also provide some aerodynamic stability passively? I...I don't know I don't know how that works but I think it's fascinating... so I think it's an amazing piece of engineering there's a newer missile a newer version over here that's the AIM-9 L...NO! M I think the first one... (Trying to remember) I read it on a thing Is it on this? Okay so the first one... so that one over there was the M the B was the first one they deployed this one is the X This is the AIM-9X so this one right here is uh... if I can focus on it let's see if I can focus up close here... So you'll notice it's different! It doesn't have pivoting blades up front it's fixed here. so we've got a Seeker... that's good.... let's move back.. don't have a proximity fuse here it's got this kind of billet here..... Warhead... Rocket... brown stripe for rocket. it's where it leaves the rail, and then way back here... look at that! So these fins pivot in the back. so it's different than the the 9-Mike over there this is the 9x ALSO, this is just a model.... but you can see anytime you have something in the rocket plume itself, that's usually an indication of thrust vector control. so I assume that means that the AIM-9X can do thrust vector control. I... I've never worked with this system so I don't know, but uh, I hear this thing is amazing. (Sarcastically) But it doesn't have rollerons (Giggles) Because.. I just think it's it's clever and interesting so... Rollerons are neat and uh I don't know much about 'em.... but it's a GENIUS solution to a difficult problem So last thing I want to talk about here... is the warhead section right here. So if you can imagine this missile is designed to engage aircraft so you've got an engine there the back of the engines there so let's say you're going for a heat signature there and it it is able to approach and acquire it would probably lead the aircraft a little bit I don't know how they do that but let's say that it gets to the end game and it wants to detonate this warhead because the side looking proximity sensor sees something well this little little warhead right here is called an expanding-rod warhead and the way it works is imagine you have a little bitty rod of steel here....here.... here.... maybe it's steel maybe it's tungsten I don't know sometimes people use tungsten because it's more dense but imagine you had all these rods stacked up in a cylinder around this thing and you were to weld this end weld two rods together and you go to the top and you go all the way over and then you weld THESE two rods together and you just zigzag back and forth... and you go all the way around the Warhead like that. Well what happens is once you have those rods welded together, and you DETONATE the explosive on the inside of that it would kind of scissor out... does that make sense? Like it's uh.... it's a cylinder and then it would kind of scissor out like that and you would have like a a torus You would take a cylinder and turn it into a disc quickly and that creates a cutter that's orthogonal to the direction of flight ...which is a really bad day if you have an engine a hot engine or an aircraft you know the idea is to damage the engine. so that is an AMAZING design and I just thought it was interesting. and I thought it would be worth talking about. So, hope you enjoyed this random discussion about a Sidewinder missile. That's it! I'm Destin you're getting Smarter Every Day. Have a good one. Bye! If look hard enough on the internet YOU CAN FIND YOUR OWN ROLLERON SIDEWINDER MISSILE FIN. Oh my goodness... (In hindsight I was perhaps too excited while opening this) it's amazing check this out.... actually works uh you can see.... they've been balanced uh yeah check it out this kind unlatches so I'm going to build something and check it out uh... I may have cut myself in the first 30 seconds I had it on this little part right here (Strong Red-Ryder BB Gun Vibes) but it doesn't matter because we got it So thank you to everybody that supports on Patreon. Patreon.com/SmarterEveryDay you just bought me some missile parts! (Giggles) OH YEAH front fins too! DUH I guess it's like that? That's a front fin. How cool is that? Okay thank you so much uh. Feel free to subscribe if you want to see what I do with this... because I have an idea... (It's cool too) Anyway, thank you very much. I'm Destin. You're getting Smarter Every Day. Have a good one. [Rolleron teeth whizzing against bubble wrap] (Whispers under breath) Aw! So cool! [Light Banjo Music]